Abduction apparatus, abduction method, and computer-readable recording medium

Abstract

An abduction apparatus 1 includes: a posterior probability calculation unit 2 that calculates, a posterior probability regarding the observation information D1 with respect to each of candidate hypotheses D3 generated using observation information D1 and knowledge information D2; a deduction probability calculation unit 3 that calculates, a deduction probability of deriving observation information D1 as a consequence of applying the knowledge information with respect to each of the candidate hypotheses; a consistency probability calculation unit 4 that calculates, a consistency probability of not contradicting the knowledge information D2 with respect to each of the candidate hypotheses; and a solution hypothesis determination unit 5 that calculates an evaluation value using the posterior probability, the deduction probability, and the consistency probability, and determines a solution hypothesis D4 that is a best explanation regarding the observation information D1, from the candidate hypotheses, based on the calculated evaluation value.

What is claimed is: 
     
         1 . An abduction apparatus comprising:
 a posterior probability calculation unit configured to calculate, a posterior probability regarding observation information with respect to each of candidate hypotheses generated using the observation information and knowledge information;   a deduction probability calculation unit configured to calculate, a deduction probability of deriving observation information as a consequence of applying the knowledge information with respect to each of the candidate hypotheses;   a consistency probability calculation unit configured to calculate, a consistency probability of not contradicting the knowledge information with respect to each of the candidate hypotheses; and   a solution hypothesis determination unit configured to calculate an evaluation value using the posterior probability, the deduction probability, and the consistency probability, and determine a solution hypothesis that is an explanation regarding the observation information, from the candidate hypotheses, based on the calculated evaluation value.   
     
     
         2 . The abduction apparatus according to  claim 1 ,
 wherein the solution hypothesis determination unit calculates the evaluation value by multiplying the posterior probability, the deduction probability, and the consistency probability, and determines the candidate hypothesis regarding which the evaluation value is largest as the solution hypothesis.   
     
     
         3 . The abduction apparatus according to  claim 1 , further comprising:
 an output information generation unit configured to generate output information in which the posterior probability, the deduction probability, and the consistency probability are given to the candidate hypothesis, and that is to be output to an output device.   
     
     
         4 . The abduction apparatus according to  claim 3 ,
 wherein the output information generation unit generates proof tree information for outputting a proof tree structure to the output device using the observation information, the candidate hypothesis, the posterior probability, the deduction probability, the consistency probability, and the solution hypothesis.   
     
     
         5 . An abduction method, comprising:
 calculating, with respect to each of candidate hypotheses generated using observation information and knowledge information, a posterior probability regarding the observation information;   calculating, with respect to each of the candidate hypotheses, a deduction probability of deriving observation information as a consequence of applying the knowledge information;   calculating, with respect to each of the candidate hypotheses, a consistency probability of not contradicting the knowledge information; and   calculating an evaluation value using the posterior probability, the deduction probability, and the consistency probability, and determining a solution hypothesis that is an explanation regarding the observation information, from the candidate hypotheses, based on the calculated evaluation value.   
     
     
         6 . The abduction method according to  claim 5 ,
 wherein, in the calculating the evaluation value and the determining the solution hypothesis, the evaluation value is calculated by multiplying the posterior probability, the deduction probability, and the consistency probability, and the candidate hypothesis regarding which the evaluation value is largest is determined as the solution hypothesis.   
     
     
         7 . The abduction method according to  claim 5 , further comprising:
 generating output information in which the posterior probability, the deduction probability, and the consistency probability are given to the candidate hypothesis, and that is to be output to an output device.   
     
     
         8 . The abduction method according to  claim 7 ,
 wherein, in the generating, proof tree information for outputting a proof tree structure to the output device is generated using the observation information, the candidate hypothesis, the posterior probability, the deduction probability, the consistency probability, and the solution hypothesis.   
     
     
         9 . A non-transitory computer-readable recording medium that includes a program recorded thereon, the program causing a computer to carry out:
 calculating, with respect to each of candidate hypotheses generated using observation information and knowledge information, a posterior probability regarding the observation information;   calculating, with respect to each of the candidate hypotheses, a deduction probability of deriving observation information as a consequence of applying the knowledge information;   calculating, with respect to each of the candidate hypotheses, a consistency probability of not contradicting the knowledge information; and   calculating an evaluation value using the posterior probability, the deduction probability, and the consistency probability, and determining a solution hypothesis that is an explanation regarding the observation information, from the candidate hypotheses, based on the calculated evaluation value.   
     
     
         10 . The non-transitory computer readable recording medium that includes the program according to  claim 9  recorded thereon,
 wherein, in the calculating the evaluation value and the determining the solution hypothesis, the evaluation value is calculated by multiplying the posterior probability, the deduction probability, and the consistency probability, and the candidate hypothesis regarding which the evaluation value is largest is determined as the solution hypothesis. 
 
     
     
         11 . The non-transitory computer readable recording medium that includes the program according to  claim 9  recorded thereon, the program further causing the computer to carry out:
 generating output information in which the posterior probability, the deduction probability, and the consistency probability are given to the candidate hypothesis, and that is to be output to an output device. 
 
     
     
         12 . The non-transitory computer readable recording medium that includes the program according to  claim 11  recorded thereon,
 wherein, in the generating, proof tree information for outputting a proof tree structure to the output device is generated using the observation information, the candidate hypothesis, the posterior probability, the deduction probability, the consistency probability, and the solution hypothesis.